(Macron and his partner Brigitte Trogneux - his former school teacher. AFP)

En Marche now has more than 96,000 members and has already received 2.7 million euros ($2.9 million) in donations.

The election is currently forecast to end in a second-round runoff pitting a centre-right candidate -- likely former prime minister Alain Juppe, 71 -- against 48-year-old far-right National Front (FN) leader Marine Le Pen.

With primaries still to be contested on both left and right, Macron's chances are hard to evaluate but 38 percent of respondents to a poll published on Tuesday said he would make a good president.